It is very useful for a worker to have rapid and convenient access to a magnet for picking up small objects, removing metal splinters, identifying metals, holding papers against a metal object and the like. However most workers will not bother to carry a magnet about because it is so infrequently used. Because it is not at hand when needed, they lose the many advantages of a magnet. The same may be said of other tools that are not very large, but would be inconvenient to carry about, such as screwdrivers and line cutters. Many individuals find it less objectionable to wear an article of adornment such as a ring, because the hands are left free.
U.S. Pat. Nos. 1,174,887 issued 3/7/16 to Meriwether and 4,174,620 issued 11/20/79 to Russell teach rings with a central magnet and 2,176,052 issued 10/17/39 to Beyer teaches a bracelet with a central magnet.
The following U.S. patents teach a ring with a single tool thereon:
U.S. Pat. No. 4,667,544 issued 5/26/87 to Milo PA0 U.S. Pat. No. 2,735,321 issued 2/21/56 to Browne et al. PA0 U.S. Pat. No. 2,585,641 issued 2/12/52 to Faso PA0 U.S. Pat. No. 885,580 issued 5/26/08 to Brinn PA0 U.S. Pat. No. 1,649,699 issued 11/15/27 to Irvine PA0 U.S. Pat. No. 1,521,051 issued 12/30/24 to Shiba PA0 U.S. Pat. No. 107,016 issued 9/6/1870 to Egge et al. PA0 also Danish No. 33541 issued 8/4/24 to Osterholt PA0 USSR No. 1237408A issued 6/15/86 to Baltabaev
A finger wrench assembly in which a single tool on a holder is removably connected to a finger encircling base assembly is taught by Vukich in U.S. Pat. No. 4,332,178 issued 6/1/82. To use another tool, the first holder is removed from the base assembly and replaced by another.
In all of the above teaching, to use more than one tool, a supply of different devices must be kept close by. It would be awkward to routinely carry such a supply around.